I have no idea how that is considered a sporting cartridge.. maybe against whales.. but it's illegal to hunt them anymore.. and we don't have elephants in the US.

You sir are insane!

E

Nope, perfectly rational. And really, anything with more than 5K foot lbs is fine for elephants. The reason that a 4 bore is considered a "sporting" cartridge is because before the advent of smokeless powder, 8 bore doubles, and 4 bore singles are what was used to hunt big elephants. Generally speaking, it's loaded fairly soft - sub 20K PSI, because you only really see it on doubles and break action singles. I, however, plan on building an artillery style falling block, and load the case up north of 40K psi. since the "gun" is going to be mounted on a dampened carriage, recoil isn't a problem. The hard part in all of this is finding the time and money to build it. Honestly, any guy with a Mll and a lathe(ideally one with a big spindle hole) can build one, it's fairly straight forward. BTW, Searcy makes modern 4 bore doubles, only $85k. Oh, if you think this is bad, consider this - JD Jones at one time made something called a .950JDJ to go into a large rifle action. Then there's guy's like Ed Hubel, who's chucking 12 gauge slugs at over 2200FPS, using a heavily modded Savage 210 action with blown out .50 BMG brass and 12 gauge rims threaded onto them. go google "12 gauge FH" or "Hubel458" and read what turns up.

Sporting use exemption is generally granted to any non explosive projo cartridge that can't use military ammunition, thus making them unsuitable for armed conflict. As far as BATFE is concerned, it's just another gun, albiet a really, really big one.

And really, this is nothing - you should see what some of the guys with muzzle loading cannons have, and they're not even regulated at all.